Suction device for internal combustion engine

ABSTRACT

The suction is provided as an integral member which includes a casing having an air inlet and a plurality of ports forming outlets to the engine cylinders, a filter in the casing for filtering air flowing through the air inlet, a collection chamber in the casing for receiving air from the filter, at least one throttle valve in the casing for controlling the flow of air from said filter to said collection chamber, and a plurality of suction pipes for communicating with the respective cylinders of the engine through said outlets. The suction device can be made compact to thereby more effectively use the engine compartment of an automobile.

BACKGROUND OF THE INVENTION

The present invention relates to a suction device for supplying air andfuel to combustion chambers of an internal combustion engine, and moreparticularly to a suction device which can be constructed compactly.

In connection with a V-type internal combustion engine in which aplurality of cylinders are arranged in a V-shape, there is described aconventional suction device in U.S. Pat. Nos. 5,003,933 and 5,094,194,for example. In this conventional suction device, a plurality ofindividual suction pipes and a collector for distributing suction air tothe individual suction pipes are integrated compactly, but an aircleaner, a suction air quantity detecting means, a throttle valve, andfuel injection valves are not integrated with the suction device. Theselatter elements are individually mounted.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a suction devicewhich can be constructed compactly so as to integrate all parts from theair cleaner to the suction ports and eliminate any spaces other than anair passage for supplying suction air to an internal combustion engine,thereby making it possible to increase the space for mounting otherparts and the internal combustion engine in an engine compartment of theautomobile or to reduce the size of the engine compartment to moreeffectively use the space provided for the engine.

A casing of a suction device has such a shape as to be fitted within aspace defined between right and left banks of a V-type internalcombustion engine. The inside of the casing is partitioned into severalspaces for mounting an air cleaner, an air collector, and a plurality ofindividual suction pipes in such a manner that these elements arearranged adjacent to each other.

The air cleaner, the air collector, and the individual suction pipes arearranged adjacent to each other, being separated by a partition, therebyforming an air passage in each element. Accordingly, all partsconstituting the suction device can be integrated, and any unnecessaryspaces, other than the air passage, can be eliminated to thereby realizea suction device having a compact structure.

In summary, the present invention provides a compact suction deviceincluding all parts from the air cleaner to the suction ports.

The suction device has the following functions. Air admitted from aninlet 5 of an air cleaner 3 is introduced through a passage 6 and an aircleaner element 33 to a suction air quantity detecting means 7. Athrottle valve 8 is located downstream of the suction air quantitydetecting means 7. The air passing through the throttle valve 8 isintroduced through an air collector 10 to individual suction pipes 11corresponding to the cylinders of the engine. Thereafter, the air issucked through suction ports 4, forming outlets of the suction device,into combustion chambers 12 of the engine. The passage 6, the individualsuction pipes 11, and the air collector 10 are arranged adjacent to eachother through a partition or directly.

Further, a control unit 13 for controlling the engine is located in thepassage 6 downstream of the inlet 5 of the air cleaner 3.

According to the present invention, the suction device, including theelements from the air cleaner to the suction ports, can be made compact,to thereby effectively use the space in the engine compartment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional front view of a suction device according to afirst preferred embodiment of the present invention, as mounted on aV-type internal combustion engine.

FIG. 2(a) is a schematic sectional front view taken along line A--A inFIG. 2b, which is a schematic sectional side view of the suction device.

FIG. 3 is a schematic sectional side view of a suction device accordingto a second preferred embodiment of the present invention.

FIG. 4 is a schematic sectional side view of a suction device accordingto a third preferred embodiment of the present invention.

FIG. 5 is a view illustrating a flow of air in the suction deviceaccording to the first preferred embodiment.

FIG. 6 is an air flow diagram relating to a flow of air in the suctiondevice according to the first preferred embodiment.

FIG. 7 is a view illustrating a flow of air in the suction deviceaccording to the first preferred embodiment.

FIG. 8 is a schematic side view illustrating a positional relationbetween the suction device and the internal combustion engine.

FIG. 9 is a schematic side view illustrating a control unit in thesuction device.

FIG. 10 is a schematic sectional side view of a suction device accordingto a fourth preferred embodiment of the present invention.

FIG. 11 is a schematic diagram illustrating an air passage shown in FIG.10.

FIG. 12 is a schematic sectional side view of a suction device accordingto a fifth preferred embodiment of the present invention.

FIG. 13 is a schematic sectional side view of a suction device accordingto a sixth preferred embodiment of the present invention.

FIG. 14 is a cross section taken along the line C--C in FIG. 13.

FIG. 15 is a schematic sectional side view of a suction device accordingto a seventh preferred embodiment of the present invention.

FIG. 16 is a cross section taken along the line C--C in FIG. 15.

FIG. 17 is a schematic side view illustrating a swirl passage providedin a suction device according to an eighth preferred embodiment of thepresent invention.

FIG. 18 is a schematic plan view illustrating swirl control valvesprovided in the suction device according to the eighth preferredembodiment.

FIG. 19 is a schematic front view illustrating the swirl control valvesshown in FIG. 18.

FIG. 20 is an enlarged view of an essential part shown in FIG. 19.

FIG. 21 is an enlarged view of a modification of each swirl controlvalve in the eighth preferred embodiment.

FIG. 22 is a schematic perspective view illustrating a preferredembodiment of the swirl passage shown in FIG. 17.

FIG. 23 is a schematic perspective view illustrating another preferredembodiment of the swirl passage shown in FIG. 17.

FIG. 24 is a schematic perspective view illustrating the flows of airand fuel in forming a swirl.

FIG. 25 is a schematic sectional front view of a suction deviceaccording to a ninth preferred embodiment of the present invention.

FIG. 26 is a schematic sectional side view of the suction device shownin FIG. 25.

FIG. 27 is a cross section taken along the line C--C in FIG. 26.

FIG. 28 is a view similar to FIG. 27, showing a tenth preferredembodiment of the present invention.

FIG. 29 is a top plan view illustrating a layout in an enginecompartment of an automobile.

FIG. 30 is a cross section taken along the line X--X in FIG. 29.

FIG. 31 is a schematic sectional side view of a suction device accordingto an eleventh preferred embodiment of the present invention.

FIG. 32 is a schematic sectional front view of a suction deviceaccording to a twelfth preferred embodiment of the present invention.

FIG. 33 is a sectional side view of a suction device according to athirteenth preferred embodiment of the present invention.

FIG. 34 is a cross section taken along the line B--B in FIG. 33.

FIG. 35 is a cross section taken along the line A--A in FIG. 33.

FIG. 36 is a schematic diagram illustrating a resonance suction lengthin the suction device shown in FIG. 33 when a variable induction valveis closed.

FIG. 37 is a diagram similar to FIG. 36, when the variable inductionvalve is opened.

FIG. 38 is a sectional side view of a suction device according to afourteenth preferred embodiment of the present invention.

FIG. 39 is a cross section taken along the line B--B in FIG. 38.

FIG. 40 is a cross section taken along the line A--A in FIG. 38.

FIG. 41 is a horizontal sectional view of a preferred embodiment of thean air flow meter shown in FIG. 38.

FIG. 42 is a left side view of the air flow meter shown in FIG. 41.

FIG. 43 is a view similar to FIG. 41, showing another preferredembodiment of the air flow meter.

FIG. 44 is a schematic diagram illustrating a resonance suction lengthin the suction device shown in FIG. 38 when a variable induction valveis closed.

FIG. 45 is a diagram similar to FIG. 44, when the variable inductionvalve is opened.

FIG. 46 is a sectional side view of a suction device according to afifteenth preferred embodiment of the present invention.

FIG. 47 is a cross section taken along the line C--C in FIG. 46.

FIG. 48 is a cross section taken along the line A--A in FIG. 46.

FIG. 49 is a cross section taken along the line B--B in FIG. 46.

FIG. 50 is a sectional side view of a suction device according to asixteenth preferred embodiment of the present invention.

FIG. 51 is a cross section taken along the line B--B in FIG. 50.

FIG. 52 is a cross section taken along the line A--A in FIG. 50.

FIG. 53 is a sectional side view of a fuel gallery provided in a suctiondevice according to a seventeenth preferred embodiment of the presentinvention.

FIG. 54 is a sectional side view of the suction device including thefuel gallery shown in FIG. 53.

FIG. 55 is a sectional side view of a suction device according to aneighteenth preferred embodiment of the present invention.

FIG. 56 is a cross section taken along the line A--A in FIG. 55.

FIG. 57 is a top plan view illustrating a layout in an enginecompartment of an automobile when an engine is longitudinally mounted.

FIG. 58 is a view similar to FIG. 57, when the engine is transverselymounted.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A first preferred embodiment of the present invention is shown in FIG.1, which is a sectional front view of right and left cylinder trains 1and 2 of an internal combustion engine 20 and a suction device 21. Theinternal combustion engine 20 is a V-type internal combustion enginewherein the right and left cylinder trains 1 and 2 are so arranged as toform a V-shape, as viewed in front elevation. While the number ofcylinders in the V-type internal combustion engine 20 is six in thispreferred embodiment, it may be eight or twelve as known in the art. Thesuction device 21 has a casing including an inlet 5 to an air cleaner 3and suction ports 4 forming a plurality of outlets to the enginecylinders, the suction device 21 being located in a space definedbetween the right and left cylinder trains 1 and 2.

Thus, the suction device 21 is designed to have a compact structure.FIG. 2(a) is a sectional front view of the suction device 21 with theright cylinder train 1 not shown, and FIG. 2(b) is a sectional side viewof the suction device 21. As shown in FIGS. 2(a) and 2(b), air admittedfrom an inlet 5 of the air cleaner 3 is introduced through a passage 6and an air cleaner element 33 to a suction air quantity detecting means7. The suction air quantity detecting means 7 is an air flow meter ofany type, such as a hot-wire type, movable vane type, or Karman vortextype. A throttle valve 8 is provided downstream of the suction airquantity detecting means 7. The throttle valve 8 is electrically drivenby a motor 9 in this preferred embodiment; however, it may bemechanically driven by a wire. The air passing through the throttlevalve 8 is introduced through a collector 10 into a plurality ofindividual suction pipes 11 respectively communicating with a pluralityof cylinders of the engine 20.

More particularly, the air is sucked through the suction ports 4,forming the outlets of the suction device 21, into combustion chambers12 of the engine 20. In order to make the structure compact, the passage6 of the air cleaner 3, the individual suction pipes 11, and thecollector 10 are arranged in this order from the upper side of thesuction device in adjacent relationship to each other through partitionsor directly. The order of arrangement of these sections is not criticalto the invention, but the passage 6 of the air cleaner 3, the collector10, and the individual suction pipes 11 may be arranged in this orderfrom the upper side of the suction device. A control unit 13 is locatedin the passage 6 of the air cleaner 3 at a downstream portion thereof inconsideration of compactibility and coolability. With this arrangement,the control unit 13 can be cooled by the air flowing in the passage 6.To ensure the compactibility, the control unit 13 is located in thepassage 6 just over the top of the individual suction pipes 11 or thecollector 10. A plurality of fuel injection valves 91 for injecting fuelare respectively located in the suction ports 4 of the individualsuction pipes 11, and a plurality of air passages (swirl passages) 14for forming a swirl of air in the combustion chambers 12 arerespectively located in the suction ports 4.

Further, a plurality of swirl control valves 15 for controlling thequantity of suction air flowing through the suction ports 4 and thequantity of suction air flowing through the air passages 14 arerespectively located in the individual suction pipes 11. In thispreferred embodiment, all or at least one of the individual suctionpipes 11, the swirl control valves 15, and the fuel injection valves 91are provided on the collector 10 serving as a negative pressure chamberdownstream of the throttle valve 8. While the suction air quantitydetecting means 7 is located upstream of the throttle valve 8 in thispreferred embodiment, the detecting means 7 may be located downstream ofthe throttle valve 8. The throttle valve 8 is mounted on a member (aportion below the line A--A in FIG. 2(b)) forming the suction ports 4respectively communicating with suction ports 17 formed in the engine20.

A second preferred embodiment of the present invention is shown in FIG.3. In this preferred embodiment, the individual suction pipes 11 and thesuction ports 4 communicating with the suction ports 17 of the engine 20are formed in a single member (a portion below the line A--A in FIG. 3),and the throttle valve 8 is mounted to this member.

A third preferred embodiment of the present invention is shown in FIG.4. In this preferred embodiment, the collector 10 is formed just abovethe individual suction pipes 11. The air passing through the throttlevalve 8 is first raised to the collector 10 and then flows down into theindividual suction pipes 11. With this arrangement, the individualsuction pipes 11 are located nearer to the engine 20, so that thesuction device 21 can be easily mounted on the engine 20 with a simplestructure.

FIGS. 5, 6, and 7 illustrate the flow of suction air in the firstpreferred embodiment shown in FIG. 2(b). The air passage from the inlet6 of the air cleaner 3 to the collector 10 is formed so that the airflows along a certain plane A, as shown in FIG. 6. On the other hand,the air passage from the collector 10 to the suction ports 4 is formedso that the air flows along a certain plane B perpendicular to the planeA, as also shown in FIG. 6. Thus, the flow of suction air changes inthree-dimensional direction at the collector 10 only, thereby reducingthe suction resistance.

FIG. 8 schematically illustrates a positional relation between theinternal combustion engine 20 and the suction device 21 as viewed inside elevation. Reference numerals 22 and 23 denote a front end and arear end of the engine 20, respectively. The air inlet 5 of the suctiondevice 21 is located just above the front end 22 of the engine 20.Accordingly, when the engine 20 is longitudinally mounted on anautomobile in such a manner that the front end 22 of the engine 20 isdirected to the front of the automobile, cool air can be readilyintroduced into the air inlet 5 of the suction device 21. Further, apulley 24 and a fan belt 25 are provided at the front end 22 of theengine 20, so that there is no space for arranging the suction airquantity detecting means 7, the throttle valve 8, and a vertical passage26 (see FIG. 7) at the front end portion of the suction device 21.Accordingly, these elements are arranged at the rear end portion of thesuction device 21 just above the rear end 23 of the engine 20. In thesuction device 21, these elements are arranged behind the individualsuction pipes 11.

FIG. 9 schematically illustrates the arrangement of the control unit 13.As mentioned above, the control unit 13 is located downstream of the aircleaner element 33 in the air passage 6 of the air cleaner 3 in orderthat the control unit 13 can be cooled by cool air just introduced fromthe air inlet 5. Further, in consideration of the compactibility of thecollector 10 and the individual suction pipes 11 and the maintainabilityof the control unit 13, the control unit 13 is located above a portion29 where the collector 10 and the individual suction pipes 11 arearranged. Since the control unit 13 must be adjusted upon delivery orinspection after being manufactured, the control unit 13 is located atsuch a position that a lid (not shown) provided on the suction ports 4can be removed at a portion upstream of a throttle valve mountingportion 30.

A fourth preferred embodiment of the present invention is shown in FIG.10. In this preferred embodiment, the air cleaner element 33 is locatedin a front portion of the air passage 6 of the air cleaner 3, and thesuction air quantity detecting means 7 is located in a rear passageportion 27 downstream of the air cleaner element 33. With thisarrangement, no bent passage portion is present upstream of the suctionair quantity detecting means 7, but a long straight passage portion canbe ensured upstream of the detecting means 7, thereby reducing detectionerror of the detecting means 7. Further, the throttle valve 8 is locatedin the vertical passage 26 for the purpose of prevention of fixation ofthe valve 8 due to stain and for the purpose of improvement inmaintainability.

FIG. 11 schematically illustrates the arrangement of the air passage inthe fourth preferred embodiment of FIG. 10. The air cleaner 3, thesuction air quantity detecting means 7, the throttle valve 8, and thecollector 10 leading to the individual suction pipes 11 having the fuelinjection valves 91 are arranged adjacent to each other. That is, asshown in FIG. 11, mounting members A, B, C, and D for respectivelymounting the above elements 3, 7, 8, and 10 are connected together in anintegral or direct fashion. With this arrangement, it is possible toreduce detection error of the detecting means 7 due to suction airpulsation caused by blow-back from the combustion chambers upon fullopening of the throttle valve 8. That is, since the air passage from theair cleaner 3 to the collector 10 can be shortened, the volume of theair column in which vibration occurs can be reduced, to thereby reducethe pulsation.

A fifth preferred embodiment of the present invention is shown in FIG.12. In this preferred embodiment, a circuit 32 of the suction airquantity detecting means 7 is located inside the control unit 13,thereby saving space.

A sixth preferred embodiment of the present invention is shown in FIGS.13 and 14. FIG. 14 is a cross section taken along the line C--C in FIG.13. Referring to FIG. 14, reference numerals 11a, 11b, and 11c denoteindividual suction pipes extending along a left bank of an internalcombustion engine, and reference numerals 11d, 11e, and 11f denoteindividual suction pipes extending along a right bank of the internalcombustion engine. The individual suction pipes 11a, 11b, and 11c arearranged in a direction A, and the individual suction pipes 11d, 11e,and 11f are also arranged in the direction A. The throttle valve 8 lieson a line of symmetry between the arrangement of the individual suctionpipes 11ato 11c and the arrangement of the individual suction pipes 11dto 11f. Further, a throttle shaft of the throttle valve 8 extends in adirection B perpendicular to the direction A. This arrangement of thethrottle valve 8 is important because the throttle valve 8 is locatedadjacent to the collector 10. With this arrangement, the throttle valve8 is rotated to equally open to the left arrangement of the individualsuction pipes 11a to 11c and the right arrangement of the individualsuction pipes 11d to 11f, thereby effecting uniform distribution of airto the left and right arrangements.

A seventh preferred embodiment of the present invention is shown inFIGS. 15 and 16. FIG. 16 is a cross section taken along the line C--C inFIG. 15. In this preferred embodiment, the throttle valve 8 is mountedin a vertical passage 34. Similar to the sixth preferred embodimentshown in FIGS. 13 and i4, the throttle shaft of the throttle valve 8extends in a direction B perpendicular to a direction A of arrangementof individual suction pipes 11a to 11c or arrangement of individualsuction pipes 11d to 11f. Accordingly, uniform distribution of air toboth arrangements can be effected.

An eighth preferred embodiment of the present invention is shown inFIGS. 17 to 24. FIG. 17 schematically shows a mechanism for forming aswirl of air in a combustion chamber 50 of an internal combustionengine. A suction port 46, as a downstream end portion of an individualsuction pipe 47, is arranged adjacent to a collector 45 downstream of athrottle valve (not shown) through a partition 51 in consideration ofspace saving. A suction passage (swirl passage) 49 is formed so as toconnect the collector 45 through the partition 51 to the suction port46. Further, a swirl control valve 48 is located in the individualsuction pipe 47 between the collector 45 and an outlet 52 of the suctionpassage 49. When the swirl control valve 48 is closed, suction air isallowed to flow through the suction passage 49, whereas when the swirlcontrol valve 48 is opened, the suction air is allowed to flow primarilythrough the individual suction pipe 47. With this arrangement, thesuction passage 49 can be easily formed because the collector 45 and theindividual suction pipe 47 are adjacent to each other through thepartition 51.

FIGS. 18 to 21 show a modified arrangement of plural swirl controlvalves 48 applied to a V-type internal combustion engine. As shown inFIGS. 18 to 20, a plurality of individual suction pipes 53 and 54 of theV-type internal combustion engine are alternately arranged so as tointersect with each other at an intermediate portion in a space betweenright and left banks of the engine. The swirl control valves 48 arelocated in the individual suction pipes 53 and 54 at this intermediateportion, and are supported on a common shaft 55. If two or more supportshafts for the swirl control valves 48 were provided, an increased spacewould become necessary, causing an increase in cost. As shown in FIG.21, each swirl control valve 48 may be formed as a swirl control valve100 partially cut away, as shown by a dashed line. Further, in the casewhere each suction port has two main passages, each swirl control valvemay be formed as a swirl control valve partially cut away so as to closeone of the two main passages.

FIG. 22 shows a preferred embodiment of the suction passage 49. In FIG.22, reference numerals 56a and 56b denote two suction valves provided ineach cylinder of an internal combustion engine, and reference numeral 57denotes a surface of the connection between the individual suction pipes47 and the engine head. Two suction passages (swirl passages) 49a and49b, through which the collector 45 communicates with the suction port46, are formed on an outer wall surface of each individual suction pipe47. That is, the walls of the suction passages 49a and 49b are partiallyformed by parts 59a and 59b of the walls of the individual suction pipe47. The suction passages 49a and 49b have respective outlets 52a and 52bopening toward the suction valves 56a and 56b, respectively.

FIG. 23 shows another preferred embodiment of the suction passage 49. Inthis preferred embodiment, the outlets 52a and 52b of the suctionpassages 49a and 49b, formed adjacent to each individual suction pipe47, are open to the connection surface 57 independently of an outlet ofthe suction port 46. The outlets 52a and 52b are respectively connectedto inlets 61a and 61b of two suction passages (swirl passages) 63a and63b formed in the engine head. Outlets 62a and 62b of the suctionpassages 63a and 63b open near the suction valves 56a and 56b,respectively. With this arrangement, a strong swirl can be easily formedin the combustion chamber.

FIG. 24 shows the flows of air and fuel. Reference numerals 64a and 64bdenote the flows of air blown from the suction passages 49a and 49b,respectively, and reference numeral 65 denotes the sprays of fuelinjected from the fuel injection valve 91. The outlets 52a and 52b ofthe suction passages 49a and 49b are directed so that the air flows 64aand 64b do not directly blow against the fuel sprays 65. If the airflows 64a and 64b having a high velocity blow directly against the fuelsprays 65, the fuel sprays 65 will change their directions so as tostrike against a wall surface of the suction passage in the engine head,so that the fuel sprays 65 will not properly enter the cylinder of theinternal combustion engine. To avoid this problem, the nozzles of thefuel injection valve 91 are arranged so that the fuel sprays 65 may bedirected to central portions of the suction valves 56a and 56b, and theoutlets 52a and 52b of the suction passages 49a and 49b are arranged indirection so that the air flows 64a and 64b may be directed to outsideend portions of the suction valves 56a and 56b. Also, in the case of asingle suction valve per cylinder, the fuel spray from the fuelinjection valve may be directed to a central portion of the suctionvalve, and the air flow from the suction passage 49 directed to an outerperipheral portion of the suction valve.

A ninth preferred embodiment of the present invention is shown in FIGS.25 to 27. FIG. 27 is a cross section taken along the line C--C in FIG.26. In this preferred embodiment, a partition 70 is formed in thecollector 10 at a transversely central position thereof to define leftand right collectors 74a and 74b. Accordingly, the air passing throughthe throttle valve 8 is divided by the partition 70 to flow into theleft and right collectors 74a and 74b. Further, a variable inductionvalve 73 is mounted on the partition 70 so as to effect communicationbetween the left and right collectors 74a and 74b. The variableinduction valve 73 is operated according to an operational condition ofthe engine, thereby changing the effective suction length of anindividual suction pipe 71 or 72. That is, when the variable inductionvalve 73 is closed in a low-speed condition of the engine, the effectivesuction length can be made large, whereas when the variable inductionvalve 73 is opened in a high-speed condition of the engine, theeffective suction length can be made small.

A tenth preferred embodiment of the present invention is shown in FIG.28, which is a view similar to FIG. 27. In this preferred embodiment, apartition 75 separating the collector 10 into the left and rightcollectors 74a and 74b is extended rearwardly between two throttlevalves 77a and 77b to a downstream position of a suction air quantitydetecting means (not shown), which is located upstream of the throttlevalves 77a and 77b. Thus, an extended partition 76 is formed between thethrottle valves 77a and 77b and the suction air quantity detectingmeans. That is, an air passage where the suction air quantity detectingmeans is located is formed as a single passage, but an air passage froma downstream area of the detecting means through the throttle valves 77aand 77b to the collectors 74a and 74b is formed as dual separatepassages. The variable induction valve 73 mounted on the partition 75 inthis preferred embodiment is operated similarly to the ninth preferredembodiment shown in FIG. 27.

FIGS. 29 and 30 schematically illustrate a layout in an enginecompartment 80 of an automobile in which a suction device 81 accordingto the present invention is mounted. FIG. 30 is a cross section takenalong the line X--X in FIG. 29. The suction device 81 is located in aspace defined between left and right banks of a V-type internalcombustion engine 82. Reference numerals 83a and 83b denote spaces wherean air cleaner, a throttle valve, etc. were conventionally located. Inaccordance with the present invention, since these elements areincorporated in the suction device 81, any other parts located in thespaces 83a and 83b can be easily maintained or inspected.

An eleventh preferred embodiment of the present invention is shown inFIG. 31. In this preferred embodiment, an EGR (exhaust gasrecirculation) passage 90 is provided in the suction device 21 so thatoutlets 93 of the EGR passage 90 respectively open into the individualsuction pipes at positions downstream of the fuel injection valves 91.If an EGR device is provided in a collector 90 as in the prior art, thefuel injection valves located downstream of the EGR collector arestained by an EGR gas. To avoid this problem, the outlets 93 of the EGRpassage 90 in this preferred embodiment are located downstream of thefuel injection valves 91 to thereby prevent the staining of the valves91 by the EGR gas.

A twelfth preferred embodiment of the present invention is shown in FIG.32. In this preferred embodiment, an EGR passage 95 is connected to aswirl passage 94 for forming a swirl of air in the combustion chamber ofthe internal combustion engine. With this arrangement, suction air fromthe swirl passage 94 and EGR gas from the EGR passage 95 can beuniformly mixed in the combustion chamber.

A thirteenth preferred embodiment of the present invention is shown inFIGS. 33 to 37. FIG. 34 is a cross section taken along the line B--B inFIG. 33, and FIG. 35 is a cross section taken along the line A--A inFIG. 33. A partition 105 for equally dividing an air passage in asuction device 100 into right and left areas is provided in a collector101, a throttle portion 102 in which the throttle valve 8 is located, avertical passage 103, and an upper horizontal passage 104. Further, avariable induction valve 106 is mounted on the partition 105 so as toeffect communication between the right and left portions of thecollector 101. In the upper horizontal passage 104, the partition 105extends from the rear end of the passage 104 to an area downstream of anair flow meter 107. The air flow meter 107 is located in a single airPassage, and an air cleaner element 108 is located upstream of the airflow meter 107 in this single air passage. The purpose of provision ofthe partition 105 is to obtain a supercharging effect. That is, when thevariable induction valve 106 is closed, a supercharging effect can beobtained in a low-speed condition of an internal combustion engine;whereas, when the variable induction valve 106 is opened, the effectivepoint of the supercharging effect is shifted to a high-speed region ofoperation of the engine.

This effect will be described in detail with reference to FIGS. 36 and37. In these drawings, reference numeral 110 denotes a cylinder of theinternal combustion engine, and reference numeral 109 denotes anindividual suction pipe of the suction device 100. FIG. 36 shows aclosed condition of the variable induction valve 106. In this closedcondition, the resonance suction length participating in thesupercharging is the sum of the length of the individual suction pipe109, the length of collector 101, the throttle portion 102, the lengthof the vertical passage 103, and the length of the upper horizontalpassage 104, which distance is a considerably large length. Accordingly,the resonance frequency is low, and a resonance effect occurs in alow-speed condition of the engine. On the other hand, when the variableinduction valve 106 is opened as shown in FIG. 37, the resonance suctionlength becomes the length of the individual suction pipe 109 plus thedistance from it to the variable induction valve 106. Thus, theresonance suction length is shortened, and the resonance effecttherefore occurs in a high-speed condition of the engine. In thismanner, the resonance suction length can be changed by opening andclosing the variable induction valve 106 to thereby obtain a resonancesupercharging effect in a wide operational range of the engine.

A fourteenth preferred embodiment of the present invention is shown inFIGS. 38 to 45. FIG. 39 is a cross section taken along the line B--B inFIG. 38, and FIG. 40 is a cross section taken along the line A--A inFIG. 38. This preferred embodiment is similar to the thirteenthpreferred embodiment with the exception that the partition 105 isextended to a position upstream of the air flow meter 107 and downstreamof the air cleaner element 108 in the upper horizontal passage 104.Accordingly, the air flow meter 107 is provided so as to pass throughthe partition 105 and extend across the upper horizontal passage 104.When the variable induction valve 106 is closed, the suction length canbe made larger than that in the thirteenth preferred embodiment shown inFIG. 33. A control unit 111 is located in the upper horizontal passage104, so as to be cooled by air flow.

In this preferred embodiment, the air flow meter 107 is so designed asto measure the quantities of air flows in two air passages 121 and 122separated by the partition 105. FIGS. 41 and 42 show a preferredembodiment of the air flow meter 107. FIG. 42 is a cross section takenalong the line A--A in FIG. 41. As shown in FIGS. 41 and 42, lead wires118 are embedded in a probe 112, and two hot wires 113 and 114 areconnected to the lead wires 118. The two hot wires 113 and 114 arelocated in two air passages 116 and 117 respectively communicating withthe two air passages 121 and 122 separated by the partition 105.Accordingly, the velocities of air flows in the two air passages 121 and122 can be measured by the hot wires 113 and 114, respectively. Then, anaverage of the velocities thus measured is calculated to thereby detectthe quantity of suction air sucked into the internal combustion engine.Reference numeral 115 denotes a resistor for compensating for suctionair temperature. The resistor 115 is located in the air passage 117 inthis preferred embodiment; however, it may be located in the air passage116. FIG. 43 is another preferred embodiment of the air flow meter 107.In this preferred embodiment, the air flow meter 107 has a common airinlet 120 equally exposed to the two air passages 121 and 122 separatedby the partition 105, and has two air outlets 123 and 124 respectivelycommunicating with the two air passages 121 and 122. Further, a singlehot wire 119 is located in a common air passage formed just downstreamof the air inlet 120. With this arrangement, an average velocity of airflows in the two air passages 121 and 122 can be measured by the hotwire 119.

FIGS. 44 and 45 schematically illustrate a resonance superchargingeffect in the fourteenth preferred embodiment shown in FIG. 38. FIG. 44shows a closed condition of the variable induction valve 106. In thisclosed condition, the resonance suction length is a total distance fromthe individual suction pipe 109 to the upstream side of the air flowmeter 107. Accordingly, the resonance suction length in this preferredembodiment can be made larger than that in the thirteenth preferredembodiment shown in FIG. 36, so that an engine speed at which theresonance supercharging effect occurs can be shifted to a lower point ascompared with the embodiment shown in FIG. 36. On the other hand, whenthe variable induction valve 106 is opened, as shown in FIG. 45, theresonance suction length is shortened as shown by a wavy line similar tothe embodiment shown in FIG. 37. Thus, an engine speed range where theresonance supercharging effect occurs can be more greatly widened ascompared with the embodiment shown in FIGS. 36 and 37.

A fifteenth preferred embodiment of the present invention is shown inFIGS. 46 to 49. FIG. 47 is a cross section taken along the line C--C inFIG. 46; FIG. 48 is a cross section taken along the line A--A in FIG.46; and FIG. 49 is a cross section taken along the line B--B in FIG. 46.In this preferred embodiment, a part of the partition 105 is utilized asa substrate for a control unit 125. With this arrangement, it isunnecessary to define a special space for locating the control unit 125.The flow of suction air will be described with reference to FIGS. 47 to49. The suction air passes through the air cleaner element 108 and isthen divided by the partition 105 in the upper horizontal passage 104 asshown in FIG. 47. Then, the suction air flows down in the verticalpassage 103 and passes through the throttle portion 102 as shown in FIG.48. Then, the suction air enters the collector 101 and is led frominlets 126 of individual suction pipes to suction ports 127 of aninternal combustion engine, as shown in FIG. 49.

A sixteenth preferred embodiment of the present invention is shown inFIGS. 50 to 52. FIG. 51 is a cross section taken along the line B--B inFIG. 50, and FIG. 52 is a cross section taken along the line A--A inFIG. 50. In this preferred embodiment, a part of the vertical partition105 is utilized as a substrate for the control unit 125 similar to thefifteenth preferred embodiment shown in FIG. 46. Further, various wiringpatterns connected between the control unit 125 and various elements,such as the air flow meter 107 and the throttle valves 8, are formed onthe vertical partition 105 and a horizontal partition 140. Morespecifically, a wiring pattern 137 connected to a power switch 130 foran igniter is printed on the horizontal partition 140 and the verticalpartition 105. Similarly, there are printed on the horizontal partition140 and/or the vertical partition 105 a wiring pattern 138 connected tothe air flow meter 107, a wiring pattern 136 connected to an actuator131 for driving the variable induction valve 106, a wiring pattern 139connected to a motor 132 for driving the throttle valves 8, and a wiringpattern 135 connected to the fuel injection valves 91. With thisarrangement, no wire harnesses are required, thereby providing variouseffects, such as weight reduction, cost reduction, and space saving. Theflow of suction air in this preferred embodiment is similar to that inthe fifteenth preferred embodiment shown in FIGS. 47 to 49.

A seventeenth preferred embodiment of the present invention is shown inFIGS. 53 and 54. In this preferred embodiment, a wiring arrangement 142is built in a fuel gallery 141 connected to the fuel injection valves91. The wiring 142 is electrically connected to each fuel injectionvalve 91 to transmit a signal for controlling a valve opening timing anda valve opening period of each fuel injection valve 91. A power element143 for driving the fuel injection valves 91 and a fuel pressureregulator 144 are mounted on the fuel gallery 141. While the powerelement 143 is heated, it is cooled by fuel flowing in a fuel passage145 formed in the fuel gallery 141. The wiring 142 is connected to aterminal 146, which is in turn connected to a wiring pattern 147 leadingto the control unit 125, as shown in FIG. 54. With this arrangement, theconstruction of wiring to the fuel injection valves 91 can besimplified.

An eighteenth preferred embodiment of the present invention is shown inFIGS. 55 and 56. FIG. 56 is a cross section taken along the line A--A inFIG. 55. In this preferred embodiment, an EGR (exhaust gasrecirculation) device effective for purification of an exhaust gas isprovided. The exhaust gas from an exhaust pipe (not shown) is introducedfrom a passage 152 through a solenoid valve 151 to a passage 148. Asshown in FIG. 56, the passage 148 is formed in the vertical partition105, and communicates through branch pipes 150 respectively toindividual suction pipes 149. Accordingly, the exhaust gas is suppliedfrom the passage 148 through the branch pipes 150 and the individualsuction pipes 149 to cylinders of an internal combustion engine. Thequantity of the exhaust gas to be supplied to the passage 148 iscontrolled by the solenoid valve 151.

FIGS. 57 and 58 illustrate different layouts of a suction device 160according to the present invention in an engine compartment 165 of anautomobile 166. The layout shown in FIG. 57 represents the case where aV-type internal combustion engine is longitudinally mounted. In thiscase, since the suction device 160 is mounted between left and rightbanks 163 and 164 of the V-type internal combustion engine, the sidespaces between the engine and tires 167 are free and available, so thatother parts can be easily mounted in these spaces and maintenance onsuch parts can be easily carried out. On the other hand, the layoutshown in FIG. 58 represents the case where the V-type internalcombustion engine is transversely mounted. In this case, since thesuction device 160 is mounted between the left and right banks 163 and164 of the engine, a partition 169 between the engine compartment 165and the passenger compartment 168 can be shifted frontward in theautomobile 166. That is, the space of the engine compartment 165 can bereduced to thereby enlarge the space available in the passengercompartment 168. In this manner, various advantages can be obtainedowing to the compact design of the suction device 160.

According to the present invention, the suction device including partsextending from the air cleaner to the suction ports, is compact, so thatthe space available in the engine compartment can be effectively used insuch a manner that an additional mounting space for other parts can beprovided, maintenance can be easily carried out, and the passenger spacecan be enlarged.

We claim:
 1. A suction device for an internal combustion engine,comprising:a casing having an air inlet and a plurality of outlets; afilter for filtering air which passes through said air inlet; a throttlevalve for controlling the flow of air from the filter to a collectionchamber in the casing; a plurality of suction pipes, each suction pipehaving an inlet portion communicating with the collection chamber and anoutlet portion for connection to a respective cylinder of the engine,each outlet portion corresponding to one of the plurality of outlets ofthe casing; and a partition dividing the casing into first and secondair passages, said first passage serving as an inlet air passage, inwhich air flows generally longitudinally along a substantial lengththereof from said air inlet to a connection path communicating with saidsecond passage, said second passage serving as the collection chamber inwhich the air flows in a direction opposite to the air flow in saidinlet air passage, and wherein the plurality of suction pipes arearranged in relation to the collection chamber such that the air flow inthe suction pipes is perpendicular to the air flow in the inlet airpassage.
 2. A suction device according to claim 1, wherein the throttlevalve is provided in the connection path.
 3. A suction device accordingto claim 1, wherein the shape of the casing has a V-form correspondingto a V-arrangement of a pair of cylinder banks of the engine.
 4. Asuction device according to claim 3, wherein the throttle valve islocated at the bottom of the V-form casing.
 5. A suction deviceaccording to claim 4, wherein the suction pipes are located at thebottom of the V-form casing.
 6. A suction device according to claim 5,wherein the width of the casing is smaller than the distance between theinner sides of the pair of cylinder banks, whereby the casing can bereceived therebetween.
 7. A suction device according to claim 1, whereinthe suction pipes are arranged side-by-side and adjacent suction pipescross each other.
 8. A suction device according to claim 1, furthercomprising an airflow meter in the casing.
 9. A suction device accordingto claim 1, wherein the filter is installed in the inlet air passage.10. A suction device according to claim 1, further including a pluralityof swirl ducts in the casing, the swirl ducts extending from saidcollection chamber to said plurality of outlets.
 11. A suction deviceaccording to claim 10, further comprising a plurality of swirl controlvalves in said plurality of suction pipes for controlling the relativeflows of air from said collection chamber to said plurality of outletsthrough the plurality of suction pipes and the plurality of swirl ducts.12. A suction device according to claim 10, wherein each of said suctionpipes has two of said plurality of swirl ducts associated therewith,each of said outlets is circular, and each said suction pipe isseparated from the associated two swirl ducts of said outlets by wallsbeing chords of said circle.
 13. A suction device according to claim 1,further comprising an exhaust recirculation passage communicating withsaid plurality of suction pipe.
 14. A suction device according to claim1, further comprising a plurality of fuel injection valves and wiringassociated with said fuel injection valves, said wiring being located insaid collection chamber.
 15. A suction device according to claim 1,wherein a further partition separates the collection chamber and thesuction pipes.
 16. A suction device according to claim 1, furthercomprising an engine control unit installed in the inlet air passage.17. A suction device according to claim 16, wherein the filter isinstalled in the inlet air passage and the control unit is installeddownstream of the filter.
 18. A suction device according to claim 1,further comprising a control unit installed on an outer surface of thecasing and cooled by an air flow in the casing.
 19. A suction deviceaccording to claim 1, wherein a wall divides said collection chamberinto first and second regions, some of said suction pipes communicatingwith said first region and others of said suction pipes communicatingwith said second region, the device including a control valve in saidwall for controlling air pressure between said first and second regions.20. A suction device according to claim 19, wherein said wall alsodivides said inlet air passage into first and second regions.
 21. Asuction device according to claim 19, wherein said at least one throttlevalve comprises first and second throttle valves, said first throttlevalve communicating with said first region and said second throttlevalve communicating with said second region.
 22. A suction deviceaccording to claim 19, wherein an electrical circuit of an enginecontrol unit is mounted on said wall.
 23. A suction device according toclaim 19, wherein an airflow meter is mounted on said wall.
 24. Asuction device according to claim 1, wherein the throttle valve isinstalled between the filter and the collection chamber.
 25. A suctiondevice for an internal combustion engine, comprising:a casing having anair inlet and a plurality of outlets; a filter for filtering air whichpasses through said air inlet; a collection chamber disposed in thecasing for receiving air from the filter; a connection path connectingan outlet of the filter to the collection chamber; a throttle valve,included in the connection path, for controlling the flow of air fromthe filter to the collection chamber; and a plurality of suction pipes,each suction pipe having an inlet portion communicating with thecollection chamber and an outlet portion connected to a respectivecylinder of the engine, each outlet portion corresponding to one of theplurality of outlets of the casing, with said casing forming a wall ofsaid collection chamber and said connection path.